In our daily life or work, from time to time we need to fetch a certain amount of liquid, such as liquid medicine and chemical reagent. In order to get the needed amount of liquid, we often need to use scaled bottles or scaled straws, or, we may pour the liquid into a flask or measuring cup before use it. The shortcomings are: 1. too many steps in the fetching procedure are involved, and it is easy to contaminate, 2. the procedure for repeated observing and pouring the exact amount of liquid is lengthy and boring, and it is hard to be precise, 3. for the old people, children and people not being well educated, they may have difficulties in correctly understanding and precisely handling the scales of the measuring tools and the containers, making it inconvenient to use in their daily life. Some people can only estimate the medicine they have fetched, leaving a significant discrepancy in quantity and affecting the effect of the medicines. In addition, while pouring the medicines, it's hard to avoid a small quantity of medicine that flows down along the mouth of the flask.